Lifting-jack.



G. E. HYLANDER.

LIFTING JACK.

APPLICATION FILED SEPT. 22, 1909.

Patented Dec. 6, 1910.

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LIFTING JACK. .APPLIOATION FILED SEPT. 22, 1909.

977,450. Patented Dec. 6,1910.

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" UNITED STATES PATENT OFFICE.

CHARLES E. HYLANDEB, OF PITTSBURG, PENNSYLVANIA, ASSIG-NOR TO THE DUFF MANUFACTURING COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

LIFTING-JACK.

To an whom it may concern:

Be it known that I, GHAnLEs E. HY- LANDER, of Pittsburg, Allegheny county, Pennsylvania, have'i'nvented a new and useful Improvement in Lifting-Jacks, of which the followin is a full,-clear and exact description, re erence being had to the accompanying drawings, forming part of this specification, in which 1 Figure 1 is a side elevation. partially in section of a jack with myimproved device attached; Figs. 2 and 3 are similar views showing the operating mechanism in different positions and placed in a horizontal position for moving an object laterally; and Figs. 4, 5 and 6 are sectional views of a double-acting jack.

My invention relates to lifting jacks, in which'the lifting bar is raised step by step by means of a pawl, which is actuated by an operating lever.

The precise nature of my invention will be best understood by reference to the accompanying drawings, which will now be described, lt being premised, however, that various changes may be made in the details of construction and general arrangement of the parts, without departing from the spirit and scope'of my invention, as defined in the ap ended claims.

Figs. 1, 2 and 3 of the drawings, the numeral 2 designates the frame of the jack. Mounted so as to slide longitudinally in the frame is a lifting bar 3, which is rovided at its lower end with a toe 4, which may be used for engaging a log or similar object which is to be shifted. The upper end of this bar is rovided with a pivoted head 5, and one si e of the bar is provided with a rack 6. Pivotally mounted in the frame 2 on a pin 7 is an operating lever 8, and pivotally mounted on the lower end of this operating lever is a lifting pawl 9, which is adapted to be held by gravity in a proper position to engage the teeth of the rack 6, when the jack is in a vertical or horizontal position. Pivotally mounted in the frame 2, 1n the in 10, is a holding pawlll, which is also adapted by means of gravity to engage the teeth of the rack 6, and hold the lifting bar 3 with its load in the position to which it has been raised by means of the pawl 9, as'hereinafter described. Pivotally mounted on the pawl 9 is a trip 12, which is provided with Specification of Letters Patent.

Patented Dec. 6, 1910.

Application filed September 22, 1909. Serial No. 519,047.

a cam portion 13 and'a finger or projection 14. 15 is a cam surface or projection on the frame 2, in line of movement of the cam 13, and 16 is a stop on the frame for'the finger 14.

Assuming the parts of the jack to be in the position shown 1n Fig. 1, and it is desired to lift a load which is supported on the head 5, the operating lever 8 is depressed, which will raise the lower end thereof and with it the pawl 9, elevating the lifting bar the distance of one tooth. As soon as the bar has been raised the distance of one tooth, the pawl 11 will drop by means of gravity into the third tooth or the next tooth from that in which it is shown in Fig. 1. The operating lever 8 is now elevated and the pawl 9 will recede from the fourth tooth to engage with the fifth tooth, and the operation will be repeated to raise the lifting bar another tooth. If it is desired to return the lifting bar, the operating lever S is raised to the position shown in Fig. 1, and the pawl 9 is raised out of engagement with the teeth of the rack and the trip 12 is rotated so that a shoulder 17 thereon engages a projection 18 on the frame, as shown in Fig. 3. The operating lever is now depressed and the upward movement of the lower end of the lever will raise the pawl 11 out of engagement with the rack, as shown in Fig. 3. If the jack is to be used in an inclined-or horizontal position, as shown in Figs. 2 and 3, for advancing an object laterally, the trip lever 12 will assume the position shown in Fig. 2, when the lever 8 is depressed. In this position, the finger 14 will engage the face 16-of the frame. \Vhen the lever is raised and the pawl 9 is retracted, the toe 13 of the trip 12 will engage the cam face 15 and hold the trip out of engagement with the face 18, so that the lifting bar can be raised step by step until it has raised the load to the desired height.

In Figs. 4, 5 and 6 I have shown what is known as a double-actin jack, in which both pawls 9 and 11 are plvoted to the operating lever 8 and are normally held in engagement with the rack 6 by gravity. In this construction, the trip lever 12 is also pivoted to the pawl 9 as in Figs. 1, 2 and 3. The trip 12 is also provided with a fin er '14, which normally rests on a dog 19, which is pivotally connected in the frame 2.

In the operation of the jack, both of the pawls 9' and 11' coact with the rack bar to raise the liftin bar; or, in other words,

when the operating lever 8 is de res'sed, the

pawl 9 wil be in engagement with the rack and elevate it While the pawl 11 will be lowered to engage with the next tooth, and when.the operating lever 8 is raised, the

Y pawl 11 will raise the rack bar and the pawl elevated to the position shown in Fig. 4, so

that the load is held by means of the pawl 11. The pivoted dog 19 is then raised to allow the trip 12 to drop into the position shown in Fig. 6, so that the projection 17 a is in engagement with a projection 18 on the frame of the machine. The operating lever 8 is then depressed, which will raise both the pawls out of engagement with the rack, so that the lifting bar is free to be returned to the position shown in Fig. 4.

The advantages of my invention. result from the provision of a trip for releasing gravity-actuated pawls, from the rack on the lifting bar, and which is normally held out of operative position by engagement with the frame of the jack.

It will be readily understood by those, familiar with the art that this trip might readily be applied to any type of jack in which the lifting bar is raised by means of gravity or spring actuated pawls operated by a lever, so that when the trip is thrown into engagement with a stationary portion of the jack, the movement of the leverwill disengage the pawls from the rack.

I claim:

1. A liftingjack having a frame, a lifting v w I bar mounted for longitudinal movement in the frame, a rack on the liftin bar, a pair position and other means on the frame for retaining the trip in a position in which it holds the pawls in inoperative position; substantiall as described.

2. A llfting jack having a frame, a lifting bar mounted for longitudinal movement in the frame, a rack on the lifting bar, a pair of awls coacting with the rack to operate sai bar, a trip pivoted to one of said pawls, a projection on the frame normally cooperating with the trip to hold it in inoperative position, and a second projection on the frame arranged to be engaged by the tripto hold both pawls in inoperative position simultaneously; substantially as described.

3. A lifting jack having a frame, a lifting bar mounted for longitudinal movement in the frame, a rack on the lifting bar, a pair of pawls co-acting with the rack to operate said bar, a trip pivoted to one of said pawls, a projection on the frame normally cooperating withthe trip to hold it in inoperative position during a portion of the movement of the pawl, a cam face on the frame arranged to be engaged by a cam on the trip during the other portion of the movement of said pawl, and a second projection on the frame arranged to be engaged by the trip to hold both pawls in inoperative position simultaneously; substantially as described.

In testimony whereof, I have hereunto set my hand.

, CHARLES E. HYLANDER.

- Witnesses:

Jnssn B. HELLER, H. M. CoRwIN. 

